The Serratus Anterior

The Serratus Anterior: The Unsung Hero of Shoulder Stability in Yoga

Before diving into the second part of my Sun Salutation anatomical breakdown, it’s time to shed some light on a key muscle that often gets overshadowed by the more popular players—the Serratus Anterior. This muscle is a powerhouse when it comes to shoulder blade stability and movement, especially during transitions in yoga, like raising your arms overhead in Upward Salute or holding a solid Plank.

Let’s break down the anatomy, biomechanics, and how this muscle is crucial to your yoga practice.

Anatomy of the Serratus Anterior: Sawing Through Stability

The Serratus Anterior is a funky-looking muscle, with a saw-like structure that attaches to the upper eight or nine ribs on the side of your chest. These attachments are what give the serratus its distinctive, serrated look—hence the name “Serratus,” which comes from the Latin “serrare,” meaning “to saw.”

This muscle runs between your ribs and the shoulder blade, where it attaches along the medial (inner) border of the scapula. When it contracts, the serratus protracts your shoulder blades—essentially pulling them forward and around the rib cage. This movement is crucial for shoulder blade stability and plays a starring role in everyday movements like reaching forward or raising your arms overhead.

Nerve Innervation: What’s Powering the Serratus?

The long thoracic nerve (C5-C7) is the nerve responsible for the action of the Serratus Anterior. If this nerve gets compressed or damaged, you might experience a condition known as winged scapula, where the shoulder blades stick out instead of lying flat against the rib cage—a dead giveaway that your serratus isn’t firing correctly.rior.

Biomechanics: How the Serratus Works in Yoga

The serratus anterior is like the stabilizer of the shoulder blades, acting as a counterbalance to muscles like the rhomboids and trapezius, which retract the shoulder blades (pull them together). The serratus works to protract the scapula, allowing you to reach forward (think punching) and upwardly rotate the scapula, which is necessary for getting your arms overhead. That’s where it becomes key in yoga poses like Upward Salute (Urdhva Hastasana), Plank, or even transitioning into Chaturanga.

During Plank and Chaturanga, the serratus anterior works to keep your shoulder blades stabilized and pressed against your rib cage. Without the engagement of this muscle, your shoulder blades might wing out, destabilizing the entire shoulder girdle and setting you up for injury.

The Serratus in Action: The Boxer’s Muscle

Nicknamed the Boxer’s Muscle, the serratus anterior is responsible for that powerful protraction seen in a punch. In yoga, this protraction shows up when you push forward through the arms, like when you extend into Plank or Downward Dog, keeping the shoulder blades close to the ribcage for stability.

But that’s not all—the serratus also helps with upward rotation of the scapula. Anytime you raise your arms above your head, whether in Warrior I or Crescent Lunge, the serratus is doing the heavy lifting to help rotate the scapula upward, making it possible for your arms to extend fully overhead.

Common Issues: When the Serratus Isn’t Working

When the serratus anterior isn’t working properly, it can cause issues like winged scapula, where the shoulder blades stick out rather than lie flat against the rib cage. This condition is not only uncomfortable but can lead to further shoulder instability, pain, and dysfunction—definitely something you want to avoid in your practice.

Without proper serratus activation, you might also find yourself struggling with movements that require shoulder stability, like Chaturanga, Downward Dog, or arm balances. You might even notice a lack of strength in transitioning from Plank to Chaturanga, as the shoulder blades winging out make it harder to control the movement.

Yoga Solutions: Activating the Serratus

So, how do we engage and strengthen this muscle in yoga? Focus on poses that emphasize protraction and upward rotation. Some excellent ways to engage the serratus include:

Plank Pose: Actively push through the hands, protracting the shoulder blades and keeping them pressed against the rib cage. This ensures that the serratus anterior is firing correctly to stabilize the shoulders.
Chaturanga Dandasana: Keep the shoulder blades firm against the rib cage and avoid winging out as you lower down. If you find your shoulder blades popping out, it’s a sign that your serratus needs more love.
Upward Salute (Urdhva Hastasana): Raise your arms overhead while focusing on rotating the shoulder blades upward, allowing the serratus to assist in getting your arms fully extended.
Downward-Facing Dog: Protract the shoulder blades slightly as you press through the hands, which helps engage the serratus anterior to stabilize the shoulders.

Serratus Anterior in Sun Salutations

In Sun Salutations, the serratus anterior plays a huge role. Every time you flow through Plank, Chaturanga, and Upward Dog, this muscle is keeping your shoulder blades stable and helping you transition smoothly. If you find yourself collapsing in these poses or feeling unstable, it might be time to focus on strengthening your serratus.

As with all things in yoga, awareness is key. Bring conscious attention to the movement of your shoulder blades in these poses. Are they winging out, or are they glued to your ribcage like they should be? Are you pressing through the hands and activating the serratus to keep your shoulders strong?

Conclusion: Give the Serratus Some Love

The serratus anterior may not be the flashiest muscle, but it’s an essential player when it comes to shoulder stability in yoga. Without it, your practice can feel shaky and unstable, especially in arm balances and weight-bearing poses.

So, as you move through your practice—whether in Downward Dog, Plank, or your next Sun Salutation—take a moment to check in with your serratus. Keep those shoulder blades stable and feel the power of this often-overlooked muscle working to support your every move.